With all the important files on your smartphone — documents, irreplaceable photos and videos, for example — what are you doing to back up your device in case it’s lost, stolen or damaged?

After all, for a small device you bring everywhere, one (or more) of the three scenarios is bound to happen at some point.

There are a few solutions, such as syncing the phone with a computer via USB or inserting a microSD card (for Android) or a Lightning flash drives (for iOS) , but one of the cheapest and easiest ways to safeguard your smartphone is by taking advantage of free cloud services.

The cloud’s advantages

•Offsite protection: Cloud services can protect your data from local threats, such as theft or damage.

•Anywhere access: With cloud services, you can access all your backed-up stuff — such as documents or media — from virtually any internet-connected computer, tablet or smartphone.

•They’re free, secure: While you might only get a few gigabytes to get going, cloud services won’t cost you anything to store your files. You will need a password to access your files, and most cloud services also offer two-step authentication.

A look at the big players

You have choices when it comes to cloud services. Many of them have similar features, but here’s a snapshot of a few of the more popular picks.

•Dropbox: The granddaddy of cloud services, Dropbox supports multiple operating systems, and its clean and simple interface means it’s perhaps the easiest to use out of all the cloud providers, but it only offers 2 gigabytes of free storage — much less than other cloud providers. That said, your storage can be significantly increased via options like referring friends or linking to social media.

Upload files; send large files to someone (even if they don’t have a Dropbox account); and edit Microsoft Office files from your mobile device. If you like, you can have all captured photos and videos automatically upload to Dropbox.

Dropbox Plus costs $9.99 a month for 1 terabyte.

•Google Drive: Especially for Android users, as it’s already integrated into the operating system, Google Drive offers up to 15 GB of free storage, which is ample for most casual users, plus it works seamlessly with Gmail, allowing you to save attachments to Google Drive (or send an email right from Google Drive).

Similar to other services, once your files or folders are uploaded to your drive, you can easily invite others to view or edit (or leave comments). Along with fast search, you can enable offline viewing of specific files, scan paper documents and more.

More storage will cost you $1.99/month for 100 GB, $9.99/month for 1TB or $99.99/month for 10 TB.

But because you only get 5GB of free storage, expect to get a message about running out of space pretty quickly — especially if you’ve enabled photo and video backup. iCloud is also seamlessly woven into Mac’s Finder app, along with saving your work to the cloud via iWork, and there’s support for Windows users, too (one-time download required). Or log in at iCloud.com.

Along with documents and media, iCloud also lets you sync contacts, calendars, email and bookmarks among iOS devices, Macs and PCs. Anyone can freely use Pages (word processor), Numbers (spreadsheets) and Keynote (presentation maker) inside of iCloud, as well.

With the OneDrive app for phones and tablets, you’ll get the same 5 GB of storage for free (or 50 GB for $1.99/month), or, better yet, with an annual Office 365 Personal subscription ($69/year), which includes Word, Excel, PowerPoint, Outlook and other apps, you’ll get 1 TB of OneDrive storage. Office 365 Home ($99/year) provides 5 TB of storage for the family (up to 1 TB/user).

•Amazon Cloud Drive: Whether you use the app for mobile devices or computers, Amazon Drive gives you access to your photos, videos, music and documents (which you can edit, too). It really shines in the photo department, as Amazon Prime members ($99/year) get unlimited backup. Otherwise, it’s a reasonable $11.99/year for unlimited photo storage (and 5 GB for everything else), or $59.99/year for unlimited everything.